Lactic acid bacteria isolated from poultry with probiotic properties

HIDALGO, V. M.; IBARGUREN, CAROLINA; AUDISIO, M. CARINA; APELLA, M.CRISTINA

Jaén, España

Conferencia; ”. Food Safety under extreme conditions; 2004

Different tool are employed to eliminate or reduce the colonization in chickens by Salmonella and other pathogenic strains. These bacteria may also contaminate humans through the ingestion of infected chickens, eggs or egg-based products like ice-cream, mayonnaise, etc. A new alternative for the elimination of these pathogens could be the use of symbiotic or eubiotic supplements. Lactic acid bacteria isolated from chickens of different ages and origins were studied with the final objective of devising a probiotic supplement for the poultry industry. More than 20 strains of Lactobacillus spp were analyzed and those with inhibitory activity against Salmonella enterica serovar gallinarum, pullorum, Typhimurieum and Enteritidis, Enterococcus hirae, Listeria monocytogenes and Listeria spp. strains were selected. Out of all of the lactobacilli strains studied only 7 showed an antagonist effect against the above mentioned avian pathogens. The techniques employed with the different pathogens were spot-on-the-lawn, microplate assay, well-agar diffusion and mixed culture of each lactic acid bacteria. The Lactobacillus strains were characterized using physiological and biochemical tests, and the amplification and sequentiation of the 16S rRNA fragment. The type and concentration of lactic acid produced were determined by HPLC. The inhibitory activity of  3 of the 7 lactobacilli were attributed to lactic acid production. The chemical nature of the inhibitory substances produced by the rest of the strains selected is now being studied. Besides, the ability of those strains to grow using fructoligosacharides (FOS) as principal carbon source was also studied and their inhibitory activities did not change under these conditions. The results of theses studies are crucial to reach our goal of developing a eubiotic supplement for the poultry industry in order to eliminate or reduce Salmonella colonization in chickens, a serious economic and sanitary problem worldwide.